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Enantioselective conversion of primary alcohols to ?-exo-methylene ?-butyrolactones via iridium-catalyzed C-C bond-forming transfer hydrogenation: 2-(alkoxycarbonyl)allylation.

ABSTRACT: Upon exposure of acrylic ester 1 to alcohols 2a-i in the presence of a cyclometalated iridium catalyst modified by (-)-TMBTP, catalytic C-C coupling occurs, providing enantiomerically enriched 5-substituted ?-exo-methylene ?-butyrolactones 3a-i. Bromination of the methylene butyrolactone products followed by zinc-mediated reductive aldehyde addition provides the disubstituted ?-exo-methylene ?-butyrolactones 6a and 6b with good to excellent levels of diastereoselectivity.

SUBMITTER: Montgomery TP

PROVIDER: S-EPMC3397400 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature

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Enantioselective conversion of primary alcohols to α-exo-methylene γ-butyrolactones via iridium-catalyzed C-C bond-forming transfer hydrogenation: 2-(alkoxycarbonyl)allylation.

Montgomery T Patrick TP Hassan Abbas A Park Boyoung Y BY Krische Michael J MJ

Journal of the American Chemical Society 20120626 27

Upon exposure of acrylic ester 1 to alcohols 2a-i in the presence of a cyclometalated iridium catalyst modified by (-)-TMBTP, catalytic C-C coupling occurs, providing enantiomerically enriched 5-substituted α-exo-methylene γ-butyrolactones 3a-i. Bromination of the methylene butyrolactone products followed by zinc-mediated reductive aldehyde addition provides the disubstituted α-exo-methylene γ-butyrolactones 6a and 6b with good to excellent levels of diastereoselectivity. ...[more]

PMID: 22734694

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